The present invention generally relates to a bi-directional quick change tool-less lever and wedge actuated collet chuck, a system and/or a method for using the same. More specifically, the present invention relates to a collet chuck, a system and/or a method that may be attached to and/or that may be integrated with high speed, variable speed and/or low speed-rotary-style power tools, such as, for example, electrically driven rotary-style power tools, pneumatically-driven rotary-style power tools and/or the like. The collet chuck, the system and/or the method may provide tool-less automatic and/or tool-less manual tightening of the collet around a shank of an accessory for the rotary-style power tool. The collet chuck, the system and/or the method may provide tool-less manual loosening of the collet for accessory replacement while the rotary-style power tool is not operating. The collet chuck, the system and/or the method may be suitable for bi-directional operation of the rotary-style power tool, and the tool-less automatic tightening may occur in both clockwise and counter clockwise directions of operation.
It is generally known that variable speed rotary-style power tools are widely used to perform various mechanical operations, such as, for example, grinding, carving, polishing, cutting, drilling and/or the like. Rotary-style power tools are used by, for example, carpenters, machinists, wood workers, stone workers, manicurists, home hobbyists and/or the like. To perform the mechanical operations, various accessories are provided, each having a shank for insertion into a collet of the rotary-style power tool. The shanks of most accessories on the market are cylindrical and have a specific diameter, such as, for example, one quarter (¼) of an inch, three sixteenths ( 3/16) of an inch, one eighth (⅛) of an inch, four to six (4-6) millimeters and/or the like. Collets in existing rotary-style tools have diameters sized to receive the shanks of various accessories. The collets are tightened to exert pressure along a length of the shank of the accessory for rotary-centered operation of the accessory. Symmetrical pressure and exact sizing of the shanks and collets allow for a precise tool bit centricity and an accurate tolerance-in-round (TIR) required to operate high speed rotary devices effectively. Three-jaw-type chucks are used to secure accessories, such as, for example, drill bits of all sizes. Three-jaw-type chucks require tightening that may be accomplished by hand; however, three-jaw-type chucks do not provide the accurate tool bit centricity, the precise TIR and/or the holding forces required for high speed rotary operations.
To accomplish a desired mechanical operation, a user of the rotary-style power tool selects the appropriate accessory. The rotary-style power tool may have a lock pin button or may provide an insertion hole for receiving a post that may be inserted by the user to prevent rotation of the collet during accessory changes. In some rotary-style power tools, two wrenches are required: a first sized wrench to prevent rotation of the collet; and a second sized wrench to tighten a collet nut. The user places the shank of the accessory into the collet of the rotary-style power tool and tightens the collet nut using the second sized wrench. The user releases the lock pin button, removes the post and/or removes the first sized wrench and performs the mechanical operation with the rotary-style power tool. To remove and/or to change the accessory, the user re-engages the lock pin button, inserts the post into the insertion hole or uses first sized wrench to prevent rotation of the collet. The user locates the second sized wrench, loosens the collet nut with the second sized wrench, removes the accessory from the collet and/or inserts the accessory as needed. As a result, changing accessories in existing rotary-style power tools is time consuming and requires at least one additional tool that is separate and that must be located.
Attempts to provide quick change tool-less systems for rotary-style power tools, especially for variable and high speed rotary-style power tools, have failed to provide the desired functionality and versatility provided by systems that require additional tools or wrenches to tighten the collet. For example, it is generally known to provide a spring to pull or push directly on a tapered collet to force the collet closed. Milling machine tools use a spring to apply pressure to a tapered collet; however, a very stiff spring is needed. The stiffness of the spring requires the use of additional tools or even pneumatic pressure to relieve the spring pressure to release the shank or a v-flanged tool holder from the tapered collet or bore.
Further, providing automatic tightening of the collet during operation has been achieved only with limited success. For example, it is generally known to provide quick release collet and chuck devices such as those taught by Han et al. in U.S. Pat. No. 5,820,136 and by Huggins et al. in U.S. Pat. No. 5,921,563. Han et al. and Huggins et al. teach using longitudinal members or cam members with centrifugal forces to tighten the collet during rotational operation only. However, Han et al. and Huggins et al. have failed to employ a system to maintain adequate pressure on the collet when the rotary-style tool is operating at low revolutions per minute (RPMs) or when the rotary-style tool is not operating at all. Therefore, when RPMs are reduced, such as when a user forces the accessory onto a surface during operation, a holding power of the collet must be at its highest to counteract the forces of friction. However, the reduced RPMs create lower centrifugal forces and a lower holding power rendering the integrated collet and chuck devices of Han et al. and Huggins et al. ineffective during RPM fluctuations. The holding power is minimal when the rotary-style device is not operating. Further, the collet and chuck devices of Han et al. and Huggins et al. do not allow for manual tightening of the collet to provide cutting force while the rotary-style device is not operating. Other disadvantages of the teachings of Han et al. and Huggins et al. include their inability to provide a collet removal or size change due to the frusto-conical geometry of the collet and its complementary housing.
A need, therefore, exists for a bi-directional quick change tool-less lever and wedge actuated collet chuck, a system and/or a method for using the same. Further, a need exists for a collet chuck, a system and/or a method that may be attached as an accessory to and/or that may be integrated with high speed, variable speed and/or low speed rotary-style power driven tools. Still further, a need exists for a collet chuck, a system and/or a method that may provide tool-less automatic and/or tool-less manual tightening of the collet around a shank of an accessory. Further, a need exists for a collet chuck, a system and/or a method that may provide for a tool-less manual loosening of the collet and subsequent accessory exchange while the rotary-style power tool is not operating. Further, a need exists for a collet chuck, a system and/or a method that may provide maximum and symmetrical tool bit shank holding pressures before, during and/or after operation of the rotary-style power tool. Still further, a need exists for a collet chuck, a system and/or a method that may apply constant and uninterrupted pressure to the collet before, during and/or after operation of the rotary-style power tool. Still further, a need exists for a collet chuck, a system and/or a method that may have a spring actuated and/or a manually actuated wedge that may abut effort arms of the levers wherein the levers have corresponding resistance arms that abut and tighten the collet. Still further, a need exists for a collet chuck, a system and/or a method that may allow for collet ejection, replacement and/or exchange by a user. Still further, a need exists for a collet chuck, a system and/or a method that may allow for quick change of accessories for rotary-style power tools. Moreover, a need exists for a collet chuck, a system and/or a method that may be intuitive to use with little or no additional instruction required.